According to Islam, a Jinn is a living creature. They are similiar to the idea of genies that you read in stories as wild and crazy spirits or even sometimes as demons (which a lot of translations of Islamic texts substitue for Jinn). Despite the folklore, Islam doesn't teach that jinns or genies live in magic lamps. (Come on, everyone has read or seen Aladdin.) On the contrary, Islam teaches that Jinns are a unique lifeform that exists for its own purpose and that we as humans have no control over them.

Jinns are the cause of supernatural phenomena and paranormal events. Do you believe in haunted places? Possession? Invisible spirits? Psychics? UFOs? Unexplainable phenomena? John Edward? Jinns are most likely the cause. They inhabit another dimension in which you cannot see them, and they have no substance you can detect. The Quran declares that Jinns are made out of the residue of scorched fire (Quran 15:27 and 55:15). Muslim scholars have speculated for a long time that Jinns may exist in the realm of thermal energy or in the X-ray or energy wave spectrums (which can not be seen with the human eye). They may also exist in another realm or dimension, we're not quite sure.

The word "jinn" means 'hidden'. Although the word can apply to anything that you don't see, like bacteria or people hiding behind a mountain, its main usage is to point out the intelligent yet invisible creature. Jinns can see us, but we usually cannot see them.

I should point out that the belief in jinns didn't originate at the time of Muhammad(pbuh); in fact the pre-Islamic Arabs commonly held superstitious beliefs and myths concerning them and even worshipped some Jinns. The tale of Aladdin and genies (jinns) is pre-Islamic. There is a similiar belief in Judaism, that of "sheydim" which is sometimes translated as "demons" which shares most characteristics (ie. invisible, good and bad, some Jewish, connection to Solomon(pbuh)) (thanks arieh). Even the Catholic church has a belief in haunting and the genuine paranormal, but doesn't like to venture a guess as to what is the cause, whether its demons or ghosts or the dead.

Jinns can be good or evil. Evil jinns prey upon human beings by goading us into doing wrong. They usually don't have physical power, but instead contact us through our thoughts, in which they can "whisper" suggestions and other types of information into our brains. Some people say that Jinns can alter our brain waves and corrupt our thoughts. Jinns sometimes have physical power, what we consider as black magic.

Islam rejects the idea that spirits of the dead roam the earth as ghosts. Instead, Muslims believe that Jinns haunt houses and spook animals and give predictions to psychics. The Jinn can also give people nightmares. Ever had a nightmare about a big black dog with red eyes? That is said to be one of the forms that a jinn can take.

Jinns like to follow the angels around. The angels, who carry out God's orders about whose soul to take or what natural disaster will occur, often talk amongst themselves. When the jinns overhear something that is going to happen on earth, they rush that information to people who claim to be fortune-tellers and pour that knowledge into their minds, mixing in a lot of lies along the way.That way, when so-called psychics speak, they seem to know certain un-knowable things, but they often use this knowledge to give bad advice. Islam is totally against this because it contributes to leading people away from God-centered lives and towards other things. Rather the point of the fortune-telling business is to tell people what they want to hear, which is how they make their money.

The most infamous Jinn of all time is Iblis, who Muslims call "Shaytan". Shaytan and all the Jinns who follow him seek to corrupt and ruin mankind to make us forget God and move into sin. They do this by playing on our fears, desires, and emotions. If we succumb to it, we will be led into bad choices and stray from where God has tried to lead us. (By "us" I'm including everyone). The spelling of Shaytan is very close to that of Satan, but there are some big differences in how Muslims and Christians and Jewish people believe he originated. (It also sounds similiar to the Hebrew "Sheydim.") Muslims reject the Christian concept of a fallen angel, since Islam teaches that all angels are good and cannot be corrupted, since they are servants of God with no free will.

But enough about the bad side of Jinns, they weren't all created for evil. The Quran says “And I (Allah) created not the jinns and humans, except they should worship Me (Alone).” (51:56) Thus they can be muslim or non-muslim; they have free will and the ability to either believe in God or reject Him. There is actually an entire chapter in the Quran that tells how a group of Jinns decided to accept Islam; Surah 72 the Jinn. Allah(swt) has given Shaytan a respite, meaning that God is leaving him alone (for now) because he is letting Shaytan test us. That will not be forever, though.

In many aspects of their world, the Jinn are very similar to us. They eat and drink, they marry, have children and they die. The life span however, is far greater then ours. Like us, they will also be subject to a Final Reckoning by God. They will be present with mankind on the Day of Judgement and will either go to Paradise or Hell.

Although Jinns are usually invisible to us, they can take on other forms, such as animals or even men. In one hadith, Abu Tha’labah al-Khushani narrated: “The Messenger of Allah (pbuh) said: ‘The jinn are of three types: a type that has wings, and they fly through the air; a type that looks like snakes and dogs; and a type that stops for a rest then resumes its journey.” There are also hadith where a jinn was seen prowling around, but had the physical form of a large black dog with red eyes. In one case a sahabi caught a man who stole in the dark and escaped, who Muhammad(pbuh) later explained was Shaytan.

Every individual among the children of Adam (that means all human beings) has a jinn who has been appointed to be his constant companion, known as a Qareen. Basically, that means everyone has a personal Satan who follows them around and tests them. Ibn Mas’ood said: “The Messenger of Allah (pbuh) said, ‘There is not one of you who does not have a jinn appointed to be his constant companion.’ They said, ‘And you too, O Messenger of Allah?’ He said, ‘Me too, but Allah has helped me and he has submitted, so that he only helps me to do good.’” (Reported by Imam Muslim, 2814). Al-Nawawi said in his commentary on Muslim: “‘He has submitted’ … he became a believing Muslim."

Since your Qareen follows you around (and some say read your mind), they have a good impression of what plans you have made. It is by that knowledge that if you were ever to visit a fortune-teller or so-called psychic, the Jinn would "whisper" your past and future plans to them. By that method, they can tell a total stranger where they were born, their parents' names, what their career goal is, etc. The ability of a person to so vividly describe the past is one of the marks of a true fortune-teller who has made contact with the Jinn.

Allah gave powers to the jinns that He did not give to humans, as a test for them. If they oppress or harm others with them, then they will be held accountable. Some of their powers have been mentioned in the Quran, like the ability to travel extremely quickly. Some of their powers, were we to see them used, would be perceived as magic. Also, some people who claim they can perform magic are actually relying on the aid of jinns. The Dajjal (false Christ) will claim to be God and perform miracles such as bringing dead to life, but he will actually be relying on a few assistant jinns to pose as dead people and thus come to life. The Prophet Solomon (pbuh) had the power to control jinns, and possessed an army of jinns who worked for him in building and treasure hunting. One of the jinns guaranteed to him that he would travel to Yemen and bring Queen Bilqis' throne back to Jerusalem before Solomon(pbuh) could rise from where he was sitting. Another one of them pulled it off in the blink of an eye.

Jinns also eat and drink, and some even have animals of their own. There are even male and female jinns, who reproduce as we do. According to a hadith, Muhammad(pbuh) told the Muslim Jinns that they could eat any bones as long as they said "Bismillah (In the name of God)" before eating it. It is the equivalent of halal food for jinns. Also, humans aren't supposed to clean themselves [ie. after relieving oneself] with bones, since your taking their food away, and some of the jinn are Muslim, and thus your brethren in religion.

The jinn live on this earth where we do. They are mostly to be found in ruins and unclean places like bathrooms, dunghills, garbage dumps and graveyards (for the bones?). Hence Prophet Muhammad(pbuh) taught people to not to loiter around such places and take precautions when entering such places by reciting prayers. According to hadith, when he entered a toilet, he would pray "O Allah, I seek refuge with You from evil spirits, male and female.”

Because the Jinn can see us and we can't see them, we have been given tools in Islam to protect ourselves. Muhammad used to recite Surah 113 The daybreak and Surah 114 Mankind to protect himself, as well as the supplication "I seek refuge in God from the cursed Shaytan." Strength of faith and religion in general will also prevent the jinn from harming a person, so much so that if they were to fight, the one who has faith would win.

Saying "Bismillah" (In the name of God) before eating, drinking, entering one's home, and using the toilet will keep the Shaytan away during those activities. Calling the adhan will cause them to flee to miles away, but they hurry back quite quickly once its over. Also, reciting the Ayat ul Kursi (The greatest verse in the Quran) is said to banish them from your house (temporarily). Keeping it posted in a room will keep them away even longer, I believe.

Jinn is typically the name by which any unclassified Jinni are called. There are many conflicting historical documents that present the power rankings of Jinni. Various sources will describe anywhere from two to five different classes of Jinni. All people agree, however, that they are classified in more powerful positions with increasing age and wisdom. For convenience, here is the largest list.

Jann are the lowest and weakest class of genie. Jann are typically found crawling in unsanitary conditions and don’t tend to cause much harm. They are always the youngest and only know a limited number of spells.

Djinn are the most common type, but still lack power. They are reportedly the most ugly of the Jinni and are often caught in bottles or lampss. The Djinn is a typical persons idea of a genie, albeit slightly less powerful. These immature genies entertain themselves by tormenting people for the fun of it. Think The Monkey’s Paw.

Shaitans (sometimes spelled Shaytan) have a respectable amount of power. They typically know seven or eight different types of magic. Once a Jinn reaches Shaitan-level, it is assigned to a human. They abandon their small-time mischief and spend their time urging their victims to do evil. To counterbalance the evil influence of the Shaitans, a guardian angel is also assigned to the same person. In some accounts, Shaitans are shapeshifters (although limited in their shifting) and live entirely off of garbage and dirt. Yuck.

Afrits are not always included in descriptions of Jinni. They are of a power level higher than Shaitans, but other than, that not much changes. Although they could change form, Afrits would often appear in the form of an ostrich.

Jinn do not have the power to alter reality and, as such, can not truely grant three wishes. An imprisoned Jinn, however, is required to provide services for its captor. Before 900 BC, the genie was only required to grant one wish; however, the number changed to three after 900 BC. The reason for the change in legend is unknown, but most likely has to do with King Solomon, who reportedly commanded many Jinni. The services are normally not anything complicated, since the only Jinni that are imprisoned are lower class and without much knowledge of magic. There is also a certain risk involved with releasing a genie. When released, the Jinn has a certain predetermined wish that, when asked for by its captor, will allow the genie to kill the person and be freed. They also took great pleasure in twisting the wishes into disadvantageous situations.